JPH10176016A - Copolymer having improved weather resistance, graft copolymer and resin composition containing the copolymer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolymer resistant to the bleeding-out and evaporation of light stabilizer in molding and kneading and having improved light stability and weather resistance by using a specific tetramethylpiperidine monomer. SOLUTION: This copolymer is composed of (A) an aromatic vinyl monomer, (B) a vinyl cyanide monomer and (C) a 2,2,6,6-tetramethylpiperidine monomer of the formula (R<1> and R<2> are each H or CH3 ) as constituent units and contains the component C in an amount of 0.01-10wt.% based on the copolymer. Preferably, the copolymer is a graft copolymer produced by the graft polymerization of the components A, B and C to (D) a rubbery polymer. Preferably, the component A is styrene, etc., its amount is 60-90wt.%, the component B is acrylonitrile, etc., and its amount is 10-40wt.%.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copolymer, a graft copolymer and a resin composition containing the copolymer, in which the bleed out of additives is small and the weather resistance is improved.

[0002]

2. Description of the Related Art Acrylonitrile-styrene resin (hereinafter referred to as AS resin), which is a copolymer containing an aromatic vinyl monomer and a vinyl cyanide monomer as constituent units, and rubber-reinforced acrylonitrile-butadiene- Styrene resin (hereinafter referred to as ABS resin) and the like are widely used because they have excellent moldability and chemical resistance and have relatively good appearance. However, AS resin and ABS resin reinforced with rubber do not have good light stability and weather resistance.
A light stabilizer is kneaded and used.

[0003]

SUMMARY OF THE INVENTION
Various methods for improving the light stability and weather resistance of S resin and rubber-reinforced ABS resin can be kneaded with various light stabilizers, and the production method is simple. There is a problem that the bleed-out or volatilization causes contamination of a mold, a roll, or the like, and that the light stabilizer bleeds out and the weather resistance of the polymer is deteriorated when used for a long time.

An object of the present invention is to provide an aromatic vinyl monomer and a vinyl cyanide monomer having improved light stability and weather resistance, in which the light stabilizer does not bleed out or volatilize during molding and kneading, as essential components. To provide a copolymer obtained by polymerizing a monomer mixture.

[0005]

In order to solve these problems, the present inventors have made intensive studies on chemically bonding a light stabilizer to an AS resin or a rubber-reinforced ABS resin. As a result, the reactive light stabilizer 2,
It has been found that a method of copolymerizing a 2,6,6-tetramethylpiperidine monomer with the AS resin or rubber-reinforced ABS resin or the like most effectively improves mold and roll stains and weather resistance. .

The gist of the present invention is to provide an aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and 2,2,6,6-tetramethyl having the following structure: The copolymer (I) and the rubbery polymer (D) each having a piperidine monomer (C) as a constitutional unit and having a content of (C) of 0.01 to 10% by weight in the copolymer are aromatic vinyls. Copolymer obtained by graft polymerization of a monomer (A), a vinyl cyanide monomer (B) and a 2,2,6,6-tetramethylpiperidine monomer (C) having the structure shown below (II) and their resin compositions.

[0007]

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[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail.

The copolymer (I) of the present invention comprises an aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and 2,2,6,6- The tetramethylpiperidine monomer (C) is used as a structural unit.

Examples of the aromatic vinyl monomer (A) include vinyl toluenes such as styrene, α-methylstyrene and p-methylstyrene, halogenated styrenes such as p-chlorostyrene, and pt-butyl. Styrene, dimethylstyrene, vinylnaphthalenes and the like can be used, and styrene or α-methylstyrene is preferable as a raw material of the resin. These aromatic vinyl monomers can be used alone or in combination of two or more.

The aromatic vinyl monomer (A) unit accounts for 60 to 90% by weight, preferably 65 to 8% by weight of the copolymer (I).
Preferably, it is contained at 5% by weight. If it is less than 60% by weight, the moldability tends to deteriorate, and if it exceeds 90% by weight, the toughness of the resin tends to decrease.

As the vinyl cyanide monomer (B), acrylonitrile, methacrylonitrile, vinylidene cyanide and the like can be used, and acrylonitrile is preferred as a raw material of the resin.

The vinyl cyanide monomer (B) unit accounts for 10 to 40% by weight, preferably 15 to 40% by weight, of the copolymer (I).
Preferably, it is contained at 35% by weight. If the amount is less than 10% by weight, the toughness of the obtained copolymer tends to decrease, and if it exceeds 40% by weight, the moldability tends to deteriorate.

In addition to these aromatic vinyl monomers and vinyl cyanide monomers, other monomers copolymerizable therewith can be copolymerized. Examples of these monomers include unsaturated carboxylic acid ester monomers, unsaturated dicarboxylic anhydrides and unsaturated dicarboxylic acid imide compounds. These may be used alone or in combination of two or more. it can.

Examples of the copolymerizable unsaturated carboxylic acid ester monomers include methyl acrylate, ethyl acrylate, n-butyl acrylate, and 2-acrylic acid.
Examples include ethylhexyl, n-hexyl acrylate, methyl methacrylate, and ethyl methacrylate. These unsaturated carboxylic acid ester monomers can be used alone or in combination of two or more.

As the copolymerizable unsaturated dicarboxylic anhydride, maleic anhydride, itaconic anhydride, citraconic anhydride and the like can be used, and maleic anhydride is preferred.

Examples of copolymerizable unsaturated carboxylic acid imide compounds include maleimide, N-methylmaleimide, and N-methylmaleimide.
-Butylmaleimide, N-phenylmaleimide, N-cyclohexylmaleimide and the like can be used.
Phenylmaleimide.

These other copolymerizable monomer units are preferably contained in the copolymer (I) in the range of 0 to 20% by weight, and if it exceeds 20% by weight, the toughness of the resin is remarkably increased. descend.

In the present invention, if necessary, other monomers such as glycidyl methacrylate, methacrylic acid, acrylic acid, methacrylamide, 2-hydroxyethyl methacrylate and polyethylene glycol monomethacrylate may be contained in an amount of 20% by weight or less, preferably 15% by weight or less. It is also possible to incorporate in the copolymer an amount of up to weight%.

The 2,2,6,6-tetramethylpiperidine monomer (hereinafter referred to as TMPM) in the present invention is 2,2,2, (meth) acrylic acid having the structure shown below.
6,6-tetramethylpiperidyl or 1,2,2,6,6-pentamethylpiperidyl (meth) acrylate. The feature of the TMPM is that it has a (meth) acryl group in the molecule and is excellent in copolymerizability with an acrylic monomer.

[0021]

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The TMPM is important for improving the light stability and weather resistance of the copolymer of the present invention. Particularly, the amount contained in the copolymer is important, and the TMPM is 10% by weight.
The following can sufficiently improve the weather resistance, but the content is 0.01 to 10% by weight in order to obtain sufficient weather resistance without impairing the physical properties of the copolymer of the present invention.
It is preferably about 5% by weight.

As a method for producing the copolymer (I) of the present invention, known polymerization methods can be employed, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization.

Further, the copolymer (I) and the rubbery polymer (D) are combined with an aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and a (meth) acrylate ester monomer. By blending the graft copolymer (III) in which at least one selected from the group consisting of the monomer (E) is graft-polymerized, physical properties such as impact properties can be improved.

The rubbery polymer (D) at this time includes polybutadiene, styrene-butadiene rubber (SBR),
Diene rubbers such as acrylonitrile-butadiene rubber (NBR), isoprene rubber, chloroprene rubber, acrylic rubbers such as poly (n-butyl acrylate) rubber, ethylene-propylene-diene rubber (EP rubber) and the like can be optionally used. .

The (meth) acrylate monomer (E) used in the present invention includes, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, Acrylic acid-n
-Hexyl, methyl methacrylate, ethyl methacrylate and the like. These (meth) acrylic ester monomers (E) can be used alone or in combination of two or more.

These rubbery polymers (D) are used so as to be 50% by weight or less, preferably 40% by weight or less in the resin composition. If it exceeds 50% by weight, the rigidity and moldability of the resin will be reduced.

As a method for producing the graft copolymer (III), known polymerization methods can be employed, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization.

Next, the graft copolymer (II) will be described.

The graft copolymer (II) of the present invention is prepared by using the same aromatic vinyl monomer (A) as used for the copolymer (I) in the presence of the rubbery polymer (D). And a vinyl cyanide monomer (B) and TMPM (C) by graft copolymerization.

The aromatic vinyl monomer (A), vinyl cyanide monomer (B) and TMPM (C) are grafted in an amount of 10 to 200 parts by weight based on 100 parts by weight of the rubbery polymer (D). It is preferred to copolymerize. At this time, like the copolymer (I), styrene or α-methylstyrene is preferable as the aromatic vinyl monomer (A), and acrylonitrile is preferable as the vinyl cyanide monomer (B). The content of the aromatic vinyl monomer (A) unit, vinyl cyanide monomer (B) unit and TMPM (C) unit in the graft copolymer component of the graft copolymer (II) is as follows: It is preferable in terms of physical properties that the ratio is the same as that of the copolymer (I).

TMPM is the graft copolymer (I) of the present invention.
It is important to improve the light stability and weather resistance of (I), but since rubber-like polymers such as SBR and NBR are particularly susceptible to light deterioration, it is extremely difficult to copolymerize TMPM with the rubber-like polymer. is important. TMPM in graft copolymer
Can be sufficiently improved at a content of 0.01 to 10% by weight, but 0.02 to 5% by weight to obtain sufficient light stability without impairing the physical properties of the rubbery polymer of the present invention. %
It is preferred that

As the method for producing the graft copolymer (II) of the present invention, known polymerization methods can be employed, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization.

The graft copolymer (II) is selected from the group consisting of an aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and a (meth) acrylate monomer (E). By blending a copolymer (IV) having at least one selected structural unit, a resin composition having excellent rigidity and moldability can be obtained. At this time, the copolymer (I)
Similarly to the above, styrene or α-methylstyrene is preferable as the aromatic vinyl monomer (A), and acrylonitrile is preferable as the vinyl cyanide monomer (B).
Further, as the (meth) acrylate monomer (E), methyl methacrylate, butyl methacrylate and the like are more preferable. Further, the copolymer (IV) contains an aromatic vinyl monomer (A) unit, a vinyl cyanide monomer (B) unit, and a (meth) acrylate monomer (E) unit. The amount is 35 to 90 units of the aromatic vinyl monomer (A) unit in consideration of the balance of physical properties such as rigidity and moldability.
% By weight, 5 to 40 units of vinyl cyanide monomer (B)
It is preferable that the content of the (meth) acrylic acid ester monomer (E) is 0 to 60% by weight.

As a method for producing the copolymer (IV), known polymerization methods can be employed, and examples thereof include emulsion polymerization, suspension polymerization, bulk polymerization, and solution polymerization.

Further, by using the copolymer (I) instead of the copolymer (IV), a resin composition having better weather resistance and light stability can be obtained.

The graft copolymer (II) is used so as to be 50% by weight or less, preferably 40% by weight or less in the resin composition. If it exceeds 50% by weight, the rigidity and moldability of the resin will be reduced.

Further, TM in the resin composition of the present invention
The total content of PM greatly affects the improvement of light stability and weather resistance, and is preferably copolymerized in the range of 0.01 to 10% by weight, preferably 0.02 to 5% by weight. 0.0
If it is less than 1% by weight, there is no effect of improving light resistance.
Even if it exceeds 10% by weight, weather resistance does not change and is uneconomical,
It adversely affects physical properties.

Various additives may be added to the resin composition of the present invention depending on its use. In particular, it is preferable to include an ultraviolet absorber since light stability and weather resistance are further improved. This is because the reactive light stabilizer and the ultraviolet absorber, which are the features of the present invention, have a synergistic effect to further improve the weather resistance. Any known ultraviolet absorber may be used, and examples thereof include benzotriazole-based, triazine-based, and benzophenone-based ultraviolet absorbers. Among them, Tinuvin 234 (manufactured by Ciba-Geigy),
Bleed-out during molding of a benzotriazole-based UV absorber having a molecular weight of 400 or more, such as ADK STAB LA-31 (manufactured by Asahi Denka Kogyo), or a triazine-based UV absorber having a molecular weight of 400 or more, such as Tinuvin 1577 (manufactured by Ciba Geigy). Is preferred. It is particularly preferable to copolymerize a reactive ultraviolet absorber such as RUVA-93 (manufactured by Otsuka Chemical Co., Ltd.) in that there is no bleed-out during molding and that the rubber-like polymer can be copolymerized. When the content of the ultraviolet absorber in the resin composition is 0.1% by weight or more, a sufficient effect can be obtained, and the use of 10% by weight or less which does not affect the physical properties of the resin composition is preferable. A content of 0.5 to 3% by weight, which balances physical properties and weather resistance, is more preferable.

[0040]

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the following examples unless it exceeds the gist of the present invention. Hereinafter, “parts” means “parts by weight” and “%” means “% by weight”.

Further, the weather resistance and stains during molding in the examples were evaluated by the following methods.

(Weather resistance) The sample was immersed in ion-exchanged water at room temperature for 24 hours, and then dried sufficiently to obtain an eye super UV tester (Dainippon Plastic Co., Ltd.)
(Izod impact strength) before and after the treatment for 100 hours was measured in accordance with ASTM-D256.

(Stain at the time of molding) The stain of the metal mold at the time of press molding at 180 ° C. was visually evaluated.・ ・ ・: No stain. Or almost no dirt x ... dirt.

(Examples 1 to 5) The following copolymers (A) to (C) in the ratios shown in Table 1 and the ultraviolet absorber tinuvin 1577
(Ciba-Geigy) was kneaded and extruded with a twin-screw extruder to obtain a resin composition. Table 1 shows the weather resistance of the resin composition and stains during molding.

Comparative Example 1 The following copolymers (D) and (E) and the ultraviolet absorber tinuvin 1577 were kneaded and extruded with a twin screw extruder in the proportions shown in Table 1 to obtain a resin composition. Table 1 shows the weather resistance of the resin composition and stains during molding.

(Comparative Example 2) The following copolymers (D) and (E), an ultraviolet absorber tinuvin 1577 and a light stabilizer LA-57 (tetrakis (2,2,6,6-
One part of tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate (manufactured by Asahi Denka Co., Ltd.) was kneaded and extruded with a twin-screw extruder to obtain a resin composition. Table 1 shows the weather resistance of the resin composition and stains during molding.

Copolymer (A) In a polymerization reactor provided with a 20-liter stirring device purged with nitrogen, 70 parts of styrene 30 parts of acrylonitrile 0.5 part of 1,2,2,6,6-pentamethylpiperidyl acrylate (Trade name: CG28-906, manufactured by Nippon Ciba Geigy Co., Ltd.) Methyl ethyl ketone 25 parts 1,1′-azobis (cyclohexane-1-carbonitrile) 0.4 parts Terpinolene 0.3 parts are continuously supplied to 110 ° C. While keeping the temperature inside the polymerization reactor constant, the polymerization reaction solution was continuously withdrawn by a gear pump provided at the bottom of the polymerization reactor so that the average residence time was 2 hours, and the polymerization reaction solution was kept at 140 ° C. It was allowed to stay in the heat exchanger for about 20 minutes.

Thereafter, the mixture was introduced into a twin-screw extruder at a cylinder temperature of 200 ° C., and the strand discharged from the extruder was pelletized with a pelletizer to obtain a copolymer (A).

In a 10-liter stainless steel autoclave, ion exchange water 140 parts 1,3-butadiene 90 parts Styrene 10 parts Potassium rosinate 2.5 parts Sodium dodecylbenzenesulfonate 0.2 parts Sodium hydroxide 0 .1 part Dextrose 0.2 part Diisopropylbenzene hydroperoxide 0.2 part Sodium pyrophosphate 0.1 part Ferrous sulfate heptahydrate 0.003 part was charged and heated to 50 ° C. The internal temperature was controlled to be constant at 50 ° C., and after 7 hours, the remaining butadiene was removed by steam distillation and then cooled.

To the obtained rubber latex, 0.5 part of a 1% aqueous sulfuric acid solution (as the amount of sulfuric acid) was added dropwise over 10 minutes with weak stirring, and the stirring was continued for 3 minutes after completion of the addition. Thereafter, 0.7 part of a 10% aqueous solution of potassium hydroxide (as potassium hydroxide) was added to obtain a rubber latex having a weight average particle size of 280 nm.

The obtained rubber latex 50 parts Ion-exchanged water (including those in rubber latex) 150 parts Dextrose 0.3 part Sodium pyrophosphate 0.1 part Ferrous sulfate heptahydrate 0.005 part The mixture was charged into a glass reactor equipped with a stirrer and heated to 60 ° C. Thereafter, acrylonitrile 15 parts styrene 35 parts 1,2,2,6,6-pentamethylpiperidyl methacrylate 0.2 parts (trade name ADK STAB LA-82, manufactured by Asahi Denka Kogyo KK) Reactive UV absorber RAVA- 93 (manufactured by Otsuka Chemical Co., Ltd.) A mixture of 1 part cumene hydroperoxide 0.25 part terpinolene 0.5 part was dropped over 200 minutes to carry out polymerization. After completion of the dropwise addition, 0.10 parts of cumene hydroperoxide was added, and the mixture was aged for 1 hour and cooled. The obtained latex was put into an aqueous sulfuric acid solution and solidified to obtain a white powdery graft copolymer (B).

In a 10 liter stainless steel autoclave, ion exchanged water 140 parts 1,3-butadiene 90 parts styrene 10 parts 2,2,6,6-tetramethylpiperidyl methacrylate 1 part (trade name ADK STAB LA) -87, manufactured by Asahi Denka Kogyo Co., Ltd.) Potassium rosinate 2.5 parts Sodium dodecylbenzenesulfonate 0.2 parts Sodium hydroxide 0.1 parts Dextrose 0.2 parts Diisopropylbenzene hydroperoxide 0.2 parts Pyroline 0.1 part of sodium acid salt and 0.003 part of ferrous sulfate heptahydrate were charged and heated to 50 ° C. The internal temperature was controlled to be constant at 50 ° C., and after 7 hours, the remaining butadiene was removed by steam distillation and then cooled.

To the obtained rubber latex, 0.5 part of a 1% aqueous sulfuric acid solution (as an amount of sulfuric acid) was added dropwise over 10 minutes with weak stirring, and the stirring was continued for 3 minutes after completion of the addition. Thereafter, 0.7 part of a 10% aqueous solution of potassium hydroxide (as potassium hydroxide) was added to obtain a rubber latex having a weight average particle size of 280 nm.

The obtained rubber latex 40 parts Ion-exchanged water (including those in rubber latex) 150 parts Dextrose 0.3 part Sodium pyrophosphate 0.1 part Ferrous sulfate heptahydrate 0.005 part The mixture was charged into a glass reactor equipped with a stirring group, and heated to 60 ° C. Then, acrylonitrile 15 parts styrene 45 parts 2,2,6,6-tetramethylpiperidyl methacrylate 0.6 parts (trade name ADK STAB LA-87, manufactured by Asahi Denka Kogyo KK) cumene hydroperoxide 0.25 parts terpinolene A mixture consisting of 0.5 parts was added dropwise over 200 minutes to carry out polymerization. After completion of the dropwise addition, 0.10 parts of cumene hydroperoxide was added, and the mixture was aged for 1 hour and cooled. The obtained latex was put into an aqueous sulfuric acid solution and solidified to obtain a white powdery graft copolymer (C).

Copolymer (D) A copolymer obtained by the same method as copolymer (A) except that CG28-906 was not used.

Copolymer (E) A copolymer obtained by the same method as copolymer (C) except that LA-87 was not used.

[0057]

[Table 1]

[0058]

The copolymer, graft copolymer and resin composition of the present invention exhibit excellent light stability and weather resistance, in which the light stabilizer does not bleed out or volatilize during molding and kneading. It is suitable for applications such as home appliances, automobile interior and exterior, equipment and building materials.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08F 220: 42 220: 34) (72) Inventor Yasuaki Ii 20-1 Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Otake Business Inside

Claims (5)

[Claims] 1. An aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and a 2,2,6,6-tetramethylpiperidine monomer (C) having the following structure:
Is a structural unit, and the content of (C) is 0.01 in the copolymer.
Copolymer (I) which is 10 to 10% by weight. Embedded image 2. An aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and a 2,2,6,6-tetramer having a structure shown below in a rubbery polymer (D). A graft copolymer (II) obtained by graft polymerization of a methylpiperidine monomer (C). Embedded image 3. An aromatic vinyl-based monomer (A), a vinyl cyanide-based monomer (B), and a (meth) -containing copolymer (I) and a rubbery polymer (D) according to claim 1. A resin composition comprising a graft copolymer (III) obtained by graft-polymerizing at least one selected from the group consisting of acrylic acid ester monomers (E). 4. The graft copolymer (II) according to claim 2.
And at least one component selected from the group consisting of an aromatic vinyl monomer (A), a vinyl cyanide monomer (B) and a (meth) acrylate monomer (E). A resin composition comprising the polymer (IV). 5. A resin composition comprising the copolymer (I) according to claim 1 and the graft copolymer (II) according to claim 2.